Polyamino acid agents can be used in detergent compositions as builders or dispersing agents. Such disclosure is given in EP 454126 which described polyamino acids, including polyaspartic acid, as biodegradable builders/co-builders in the formulation of detergents. The said polymers, especially those derived from aspartic acid, glutamic acid and mixtures thereof, are described as resistant to heat, stable to pH, non toxic, non irritant and entirely biodegradable. However, a problem encountered by such use is the degradability of those polymers under storage and over a period of time. PCT/US93/12090 discloses the use of polyamino acid protected from contact with a level of alkalinity as would cause degradation thereof. The said polyamino acid is provided with a coating, encapsulated or mixed in the form of an agglomerate or granulate with at least one other material which is preferably an alkaline or alkaline reacting compound. However, research by the present Applicant has revealed that this kind of protection will also degrade under storage. This being `partially` due to the enzymatic action and alkaline hydrolysis.
It has now been found that a detergent composition containing a detersive surfactant, at least one polyamino acid compound and at least one protein wherein said polyamino acid compound and said protein are in close physical proximity shows enhanced storage stability.
A further advantage to the close physical proximity of said polyamino acid compound and said protein is the enhanced stability and protection against bleaches.
It is a further object of the present invention to provide a detergent composition with effective stain and soil removal performance.